1. Field of the Invention
The present invention relates to the field of networked computer systems. Specifically, the present invention relates to the field of highlighting objects displayed across a networked computer system.
2. Description of Related Art
A set of personal computers interconnected on a network can be effectively used as a conferencing system. In such a system, each conference participant comprises a personal computer user having a computer, a display screen, a computer network interface, and typically a mouse or cursor movement device. Conference participants are linked together over a computer network or other data communications medium. This network may comprise either a hard wired local area network (LAN) such as Ethernet, a telephone modem link, or other conventional data communications network. Because the conference participants are linked via a computer network, the participants do not need to be located in the same physical space. Rather, an effective conference may be carried out as participants view common information over their display screens and manipulate the information using their cursor devices or other input devices.
Several problems with these conferencing systems exist in the prior art. Conventional conference participants typically have a cursor movement device, such as a mouse or trackball device, connected to their system. This cursor movement device provides a means for moving a visible cursor symbol around on the user's computer display screen. In this manner, a user may manipulate a local cursor symbol. It is also advantageous for a conference participant to manipulate displayed symbols or annotations on the display screen of other conference participants. It would be advantageous for a first conference participant to manipulate a remote symbol on the display screen of a second conference participant using the cursor movement device of the first conference participant's computer system. The manipulation of a remote symbol is particularly useful for highlighting portions of a remote conference participant's display screen. For example, it would be advantageous to highlight portions of text on a remote screen using a local cursor movement device. Prior art systems cannot effectively provide this highlighting capability in a conferencing system. Further, prior art methods of combining symbols or displayed images typically causes an undesired effect on the color of the combined image. The prior art method of combining images using an exclusive OR process produces this undesired effect.
Thus, a better means for highlighting information between conference participants in a computer conferencing system is needed.